1. Field of the Invention
The present invention broadly relates to computer system configurations and housings.
2. Description of the Related Art
Modern computer systems generally include a housing or an enclosure, a display device and an external command/data input device. The display device may be a CRT (cathode ray tube) monitor, e.g., in a desktop computer system, or it could be a TFT (thin film transistor) screen, e.g., in a portable laptop computer. The external input device may be a keyboard, a pointing device, e.g., a mouse, or a combination of them. The system housing is an enclosure that houses the hardware components that perform, along with necessary software, various processing tasks as requested by the user. The housing may also include one or more power supplies to supply proper electrical power to various electronic hardware circuit elements. Auxiliary storage device drives, e.g., a floppy disk drive or a CD-ROM drive may also be housed within the computer system housing. Additionally, hard disk drive for large amount of data storage is almost invariably included within the computer housing for greater digital information storage capacity.
Electronic components or hardware circuit elements include semiconductor devices. During operation, such electronic components dissipate electrical power (i.e., transform electrical energy into heat energy). At the same time, several key operating parameters of semiconductor electronic devices typically vary with temperature, and reliable device operation within specifications occurs only within a defined operating temperature range. For example, specified performance of a processor is typically achieved only when the temperature of the processing device or xe2x80x9cprocessorxe2x80x9d, e.g., one or more microprocessors, is maintained below a specified maximum operating temperature. Operation of the processor at a temperature above the maximum operating temperature may result in irreversible damage to the processor. In addition, it has been established that the reliabilities of semiconductor electronic devices decrease with increasing operating temperature.
The heat energy produced by electronic components during operation must thus be removed to a surrounding ambient at a rate which ensures that operational and reliability requirements are met. As component speeds, capabilities and density increase, so does the amount of electrical power dissipated by the components during operation. Cooling mechanisms employed by computer systems must thus allow for more guided airflow into the housing for faster heat transfer from the computer system enclosure to the surrounding ambient.
Today, a typical computer system includes various openings or vents on one or more of the side panels for the housing and/or sometimes on the front bezel itself. The front bezel generally includes power and reset buttons for the system and typically includes areas to allow a user to load CDs and/or floppy disks into corresponding disk drives. The various openings or vents, in conjunction with one or more fans mounted on a metal chassis or included within an appropriate hardware unit, e.g., the power supply unit, allow ambient air to flow into the computer system housing and over the electronic hardware components within the housing, absorbing heat energy from the components before being expelled through the openings or vents in the rear of the metal chassis.
In some computer systems, an independent fan is attached to a heat sink mounted to the processor. However, as the number of processors within the system increases, additional fans or cooling mechanisms are needed to efficiently expel the heat generated by these processors. Fans are rotating electromechanical devices which produce acoustic noise and fail relatively often (i.e., have relatively short operating life). When a fan fails, the components that rely on the cooling air provided by the fan can, and often do, fail as well. Further, fans are relatively heavier in weight, and increasing the number of fans may increase the weight of the computer system housing. Therefore, a computer system housing where adequate component cooling is achieved without undue multiplicity of cooling fans may be desirable.
The power supply unit normally produces more heat energy than most of the other electronic components. It may also be desirable to have a computer system chassis that keeps the power supply unit and its cooling system physically separated from the rest of the system hardware mounted on the chassis so as to reduce heat dissipation around the rest of the system hardware.
The enclosure for computer system components has a limited volume. The expandability of system processing power or system storage capacity, e.g., on-board caches and RAMs (Random Access Memory), depends, among other factors, on the size or volume of the computer system housing. Further, increase in the number of electronic components that are housed within the enclosure may necessitate proportionate availability of adequate cooling means for reliable operation of the computer system. Therefore, it may be desirable to optimize the component packing density within the housing while maintaining proper airflow through the computer system components for adequate cooling.
The problems outlined above may in large part be solved by a computer system housing as described herein. The housing includes a metal chassis that provides a frame or structure to mount a number of computer system components on. In one embodiment, the metal chassis may be partitioned into two separate sub-chassis. The partitioning of the system chassis may allow for flexible manufacturing of different configurations of the computer system, for example, when the requirements for computer system component packing density or for the size of the power supply unit are variable. Due to the separate tooling of the two sub-chassis, only one of the sub-chassis may be retooled in view of the changed configuration requirements.
The front of the computer system chassis (i.e., the side of the computer system chassis that generally faces a user when the housing is placed in an upright position over a surface) may be covered with a bezel that forms a first sideways gap (e.g., on the left side) between the front of the chassis and the bezel surface. The sideways gap extends perpendicularly from the front of the chassis to a predetermined width and stretches to a predetermined length along the front of the chassis. A second sideways gap (e.g., on the right hand side) may also be formed by the bezel when attached to the front of the chassis. The sideways gaps may allow efficient cooling of system components due to the increased air inlet from the sides.
The bezel surface may be formed with a predetermined curvature to obtain desired sideways air inlet area. The fans mounted at different locations on the metal chassis may draw air from the sideways air inlets and cool appropriate hardware components before expelling the heat-containing air to the surrounding ambient through one or more vents provided on the rear side of the chassis. In one embodiment, one or more cooling fans may be mounted on the chassis without screws. Fans may be configured to snap into a corresponding bracket, and the bracket may be configured to snap into the chassis without requiring any screws.